PNG vs JPG: When to Convert Between Them (and How to Keep Quality)

In this article (6 sections)

What each format does
When to convert PNG to JPG
When to convert JPG to PNG
Quality settings
Converting a batch
Make files smaller without changing format

PNG and JPG are the two formats you meet every day, and converting between them is one of the most common image jobs. The wrong choice either makes a file far bigger than it needs to be or makes a crisp graphic look fuzzy. The deciding questions are simple once you know what each format is for.

What each format does

JPG (or JPEG) compresses by throwing away detail the eye barely notices. It is excellent for photographs and has no transparency. Every time you save it again, a little more detail is lost.
PNG keeps every pixel exactly and can store transparent and semi-transparent areas. It is the right format for logos, icons, screenshots, diagrams and anything with sharp edges or text. Files are larger, especially for photographs.

When to convert PNG to JPG

Convert PNG to JPG when a PNG is a photograph or a screenshot of a photo and the file is far larger than it needs to be. A 3 MB PNG photo can be a few hundred kilobytes as a JPG at 85 to 90 percent quality with little visible change. It is also the answer when a form accepts only JPG.

The tool converts up to 30 files at once and lets you set the quality and the colour that replaces transparent areas, since JPG cannot store transparency. Choose white for documents and most listings, or a matching colour for a dark site. If you need the transparency, do not convert to JPG at all.

When to convert JPG to PNG

Convert JPG to PNG when you need to edit repeatedly without further loss, when you want to add transparency later, or when a program requires PNG. It does not recover detail the JPG already lost, and the PNG will be larger, often much larger. It also does not add a transparent background; it only stores what the JPG contains.

Quality settings

For photographs, 85 to 90 percent is a good default: visually close to the source with a moderate file size. For pictures that will be printed or edited again, use 95 or higher. Look at edges and small text after converting; sharp lines show JPG compression first. If a screenshot looks fuzzy as a JPG, keep it as PNG.

Content	Best format	Why
Photographs	JPG	Small files, no visible loss at good quality
Screenshots with text	PNG	Keeps text crisp
Logos and icons	PNG	Sharp edges and transparency
Images with transparency	PNG	JPG cannot store it
Photos for the web	JPG or WebP	Smallest files

Converting a batch

Test with two or three files and compare the results at full size.
Set the quality and the transparency fill once.
Convert the batch and download a ZIP.
Keep the originals in a separate folder.

Everything happens in your browser, so the pictures are not uploaded. For converting between PNG, JPG and WebP in any direction, the Image Converter covers all combinations, and JPG vs PNG vs WebP compares the three in more detail.

Make files smaller without changing format

Resize first. A photo shown 800 pixels wide does not need to be 4,000 pixels wide, and the Image Resizer cuts the file size more than any format change. Then compress with the Image Compressor if you need a target size.

💡Pro Tip

Do the edits in a lossless format and export a JPG once at the end. Saving a JPG over and over loses detail each time.

🎯Key Takeaway

Use JPG for photographs, PNG for sharp graphics and transparency, and convert only when the new format fits the content.